repl: no RegExp side effects

[bnoordhuis]

$ ./out/Release/node 
> RegExp.$_
'\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000'

Caused by the repl trying to fix up the side effects to RegExp.$1 toRegExp.$9. :-)

[princejwesley]

@bnoordhuis When we run from the file, the output should be empty, right?

Source: /Users/princejohnwesley/Desktop/RegExpInput.js

console.log(RegExp.$_)

output (< v8.0.0)

/Users/princejohnwesley/Desktop/RegExpInput.js

output (>= v8.0.0)

{ 'target_defaults': { 'cflags': [],
 'default_configuration': 'Release',
 'defines': [],
 'include_dirs': [],
 'libraries': []},
 'variables': { 'asan': 0,
 'coverage': 'false',
 'debug_devtools': 'node',
 'force_dynamic_crt': 0,
 'host_arch': 'x64',
 'icu_data_file': 'icudt59l.dat',
 'icu_data_in': '../../deps/icu-small/source/data/in/icudt59l.dat',
 'icu_endianness': 'l',
 'icu_gyp_path': 'tools/icu/icu-generic.gyp',
 'icu_locales': 'en,root',
 'icu_path': 'deps/icu-small',
 'icu_small': 'true',
 'icu_ver_major': '59',
 'llvm_version': 0,
 'node_byteorder': 'little',
 'node_enable_d8': 'false',
 'node_enable_v8_vtunejit': 'false',
 'node_install_npm': 'true',
 'node_module_version': 57,
 'node_no_browser_globals': 'false',
 'node_prefix': '/',
 'node_release_urlbase': 'https://nodejs.org/download/release/',
 'node_shared': 'false',
 'node_shared_cares': 'false',
 'node_shared_http_parser': 'false',
 'node_shared_libuv': 'false',
 'node_shared_openssl': 'false',
 'node_shared_zlib': 'false',
 'node_tag': '',
 'node_use_bundled_v8': 'true',
 'node_use_dtrace': 'true',
 'node_use_etw': 'false',
 'node_use_lttng': 'false',
 'node_use_openssl': 'true',
 'node_use_perfctr': 'false',
 'node_use_v8_platform': 'true',
 'node_without_node_options': 'false',
 'openssl_fips': '',
 'openssl_no_asm': 0,
 'shlib_suffix': '57.dylib',
 'target_arch': 'x64',
 'uv_parent_path': '/deps/uv/',
 'uv_use_dtrace': 'true',
 'v8_enable_gdbjit': 0,
 'v8_enable_i18n_support': 1,
 'v8_enable_inspector': 1,
 'v8_no_strict_aliasing': 1,
 'v8_optimized_debug': 0,
 'v8_promise_internal_field_count': 1,
 'v8_random_seed': 0,
 'v8_use_snapshot': 'true',
 'want_separate_host_toolset': 0,
 'want_separate_host_toolset_mkpeephole': 0,
 'xcode_version': '7.0'}}

[bnoordhuis]

@princejwesley That's right,

[BridgeAR]

I had a look at this and it seems the only way to really solve this is the solution suggested by @princejwesley in #20549.

We should either accept this as a side effect that we do not want to fix or we should revive that PR. I personally suggest we go for the latter.